32 ROYAL SOCIETY OF CANADA 
alteration was accomplished by extreme or heavy pressure and possibly 
heat which subjected the beds to such unequal strains that fractures 
were formed whereby the escape of gases was possible. 
Other coals which have anthracite characters with less ash than the 
bituminous coals are found in South Wales where the beds have been 
subjected to pressure but with little disturbance. The coal fields are in 
basin form and the carbon percentage seems to rise gradually with the 
depth, that is, seams near the eastern edge of the basin have certain 
bituminous characters or are below the anthracite grade but pass into 
anthracites at greater depths. Fault lines across the fields show no 
effect on the seams and it is supposed that the faulting was subsequent 
to the main alteration in the coal. Intrusions are not present and unless 
deep seated cannot be counted on to have raised the temperature. A 
supposition in this case may be stated as: (1). The deep parts of the 
field owes its alteration to pressure without the formation of gases. 
(2). The marginal parts, owing to less covering beds, were altered 
by the escape of hydro-carbon and carbon-dioxide gases. 
To test this theory we will take a concrete example and suppose 
that a peaty substance is altered according to each of the above sup- 
positions. 
An average peat will have the following general composition :— 
Cao. £243 OOF ee en. LEM, 50 
PLY VO RET sera ee, ME a a AO eet a 7 
Oey ee OR Lh eee eo ee 42 
ORO SOR ar ig csr cons hale eee gM cee eee: Ae eee 1 
100 
For beds that are deeply buried. 
Assume that the combinations formed, owing to pressure, were 
between hydrogen and oxygen and carbon and oxygen. For conven- 
ience we will use the combinations H,O seven parts by weight and CO, 
one part. 
The composition of the mass remaining will be:— 
For a loss of 46 per cent. 
CRPDOR US us done 89.70 
YO aBN ole xin ose Sis 4.67 
ISOM A a Te ae RD 3.78 
NISTOLER re 1.85 
100.00 
Ash 1.85 times the original. 
For a loss of 47 per cent. 
Carbon. 0s. caine 91.32 
Hydrogen...... 4.59 
OSV Rete sr." 2.21 
Nitrogen. . ..... 1.88 
100.00 
Ash 1.88 times the original. 
